In Michelle Philpots' world, Bill Clinton is still president, everyone keeps telling each other that "life is like a box of chocolates" and no one can get Ace of Base's "The Sign"out of their heads. That's because Philpots is stuck in 1994.
Visit msnbc.com for breaking news, world news, and news about the economy That year, Philpots suffered traumatic brain injuries in two car crashes. Since then, she's been unable to form new memories; every morning, her husband has to convince her that they're married, using a photo album as proof -- a real-life version of the Adam Sandler-Drew Barrymore movie "50 First Dates." She can remember everything that happened to her until 1994, but nothing after that -- not even her 1997 marriage. (She started dating her husband before her injury, but doesn't remember marrying the guy.) Philpots, 47, who lives in Spalding, England, has an extreme case of anterograde amnesia, a condition that inhibits the brain's ability to record any new memories. Other amnesiacs can't recall older memories, a condition called called retrograde amnesia. Amnesia is a handy plot device in pop culture, and memory experts say real-life "Memento" cases are rare, but they do exist. No case of amnesia is exactly alike, says Dr. Ronald Petersen, a Mayo Clinic neurologist and a member of the American Academy of Neurology. Some forget faces, some forget their native language, some "forget" their entire personality. But each case is caused by a head injury, a neurological disease or, in some cases, years of drug or alcohol abuse. Petersen, who did not treat Philpots, explains that the type of memory loss depends on what region of the brain is impacted; for example, retrograde amnesia generally happens when damage is done to the brain's temporal lobes, and both retrograde and anterograde amnesia, like Philpots has, can happen when the hippocampus is injured. But it's still not understood what makes someone's memory "reset" every 30 seconds or, in Philpots' case, every day. Petersen has also treated several patients with transient global amnesia, a temporary but terrifying form of memory loss that strikes seemingly at random. "A person is walking out in the street and all of a sudden he develops this," Petersen explains. No head injury, no evidence of disease or drug abuse -- but for as long as 24 hours, he can't form new memories or recall old ones. Other famous amnesiacs include Clive Wearing, an English musicologist, who has suffered from both retrograde and anterograde amnesia since an infection attacked his brain in 1985. His memory essentially "resets" itself every seven to 30 seconds. There's the strange case of Benjamin Kyle, who was found behind a Richmond Hill, Ga., Burger King. He was lying unconscious behind the fast-food joint, with evidence of three blows to the head. When he came to, he had no idea who he was, couldn't remember his own name and didn't even recognize his own face. (He came to be called "BK" after the restaurant where he was discovered, which evolved to Benjamin Kyle. Despite DNA searches, his real identity is still a mystery.) Do you have friends or family who've suffered from forms of memory loss? Tell us about how they've coped in the comments.Find The Body Odd on Twitter and on Facebook.